F350: 4.30 or 3.73 Gears

RCMAN46 wrote:

Chuck_thehammer wrote:
I would like the 4:30...


2 wheel drive 3:73.. very towable..

the 4:30 would allow a higher gear going up hill.. less rpms
engine is fine at 4,000 rpm's.. but body, sound, vibrations..

my opinion

The 4:30 will not allow less rpms going up a hill.

If climbing a hill requires x horsepower then the the engine will have to turn y rpm to make that horsepower.
Thus same rpm regardless of the rear end ratio provided you have a transmission that will allow the required rpm. The newer 6 and 8 speed transmissions do this very well.

There is nothing wrong with using 6 th gear with a 4:30 and 5th gear with the 3:73. The final gear ratio to the rear wheels will be very close.

Rear end Gearing does not make more power.

The rear end gears are the final torque multiplier, so the 4.30 gears will give you more power at the pavement.

Here's a simple explanation, if you have a 10 to 1 torque multiplier on a wench it will take 100 ft lbs of torque to apply 1000 lbs of torque to the bolt but if you use a 5 to 1 it will take 200 lbs of torque to get the same 1000 lbs at the bolt.

So even when using the lower transmision gear you will not get the same torque to the rear wheels when using 3.73 gears over the 4.30 gears.

Denny